Support stand



FIG. 1 is a top plan view of a support stand showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a front elevational view, the rear view being identical thereto; and

FIG. 4 is a side elevational view, the opposite side being identical thereto. 

The ornamental design for a support stand, as shown and described. 